Allowing of proxy in an General meeting

In an private limited, the company is following proxy in their own format other than the format mentioned in companies Act,1956. One member has send proxy by filling up proxy as per the format stated in companies Act,1956 to AGM the company has not allowed him to attend the AGM on the ground that the proxy is not in the format as per stated in Articles of Association of the private limited company. can a Pvt limited company do so?